A window regulator is a mechanism under which control a vehicle window, e.g. a passenger door window is raised and lowered. Various types of window regulators are known.
In modern vehicles, auto windows are generally curved, having a major outwardly convex surface. A side door window, for example, thus has a forward upright edge and a rearward upright edge, each located in an arcuate guide rail which defines a travel path followed by the window as it moves between upper and lower positions. It is in this context that advantages of the invention described herein would be most apparent.